Over the years, several mechanical and oral products have been introduced for birth control, prophylactic condoms being one of them. However, today, condoms present the only means of protection--albeit, incomplete protection--against venereal disease a.k.a., sexually transmitted diseases (STDs) in risky (extramarital) sexual activity. Among those who engage in such sexual activity, many choose not to take this precaution. Reasons why this might be so could include cost, discomfort, dissatisfaction, unavailability. I believe dissatisfaction would predominate. It is widely known that wearing a "rubber" is regarded as obligatory, and not as a natural prelude to pleasure. Condoms introduce a barrier to intimate genital contact.
U.S. Pat. No. 4,183,358 to Cohen (1980) discloses a contraceptive device that appears to solve the problem of loss of genital skin contact, but has some disturbing aspects. For example, a tube of undescribed rigidity is inserted somewhat far into a male member, after which a rigid cap covering the glans is threaded thereon. U.S. Pat. No. 2,291,191 to Scudder (1942) employs a lengthy and narrow passageway restricting fluid flow, and protrudes rigidly externally.